Why Kotlin?

Kotlin is especially interesting for Java developers.

But why? What makes Kotlin so much better than Java and what about my existing Java codebase?

That's what this page is about.

Why Kotlin?

There are many reasons why I today choose Kotlin over Java whenever possible, although having worked with Java professionally since 1.2 and having learned about other JVM languages like Scala, Groovy, Ceylon and others.

It's hard to pinpoint the single and ultimate reason - it's more the sum of all the (little and greater) things Kotlin just does better, easier, more efficient and more elegantly than Java (or any other JVM language I know of), that convinces me having found a worthy successor to Java.

But not only the much more efficient syntax is an important reason, but also Kotlin being free and open-source and its 100% Java interoperability, which enables you to easily keep using your existing Java codebase and the vast number of already existing Java libraries.

Im Folgenden möchte ich dich (oder auch deinen Chef) überzeugen, dass es sich wirklich lohnt, sich eingehend mit Kotlin zu beschäftigen und letztlich darauf umzusteigen.

100% Java Interoperability


Kotlin directly compiles to JVM byte code (and others), so you can still make use of the powerful JVM and its ecosystem like "VisualVM", debuggers, profilers etc.

Actually, when running a Kotlin application, the only difference to a Java application is a (lean) kotlin.jar run time library in the classpath, nothing else!

Mix Kotlin and Java

Kotlin is build from the ground up to work together with existing Java code - being it your very own codebase or the thousands of open-source Java libraries, which are essential for efficient development.

Important to note is, that existing Java applications can easily be extended with Kotlin code successively.

Literally, you can add your first Kotlin code to an existing Java codebase within just a few hours and start to benefit from Kotlin's features right away.